Don't think it's TPEs fault for being on time, and wouldn't be my angle.
Taking what has been said about what "technically" should have happened (which I would read as a ticking off), my angle would be that the TOC with the initial late running train is the cause (as this would be the case were the person to miss a connection normally due to a late running incoming connection). Do passenger focus accept that a passenger should always be compensated under that company's/NR delay repay rules in these circumstances?
Additionally, would they also like to explain the implications of their stance for commuters from stations with no ticket purchasing facilities, where these passengers need to connect on to services within tight timescales, in order to reliably turn up to work each day? They have a "choice" of extending their journey by perhaps 2 hours a day (1 hour each way), or risking being challenged over not having a valid ticket and not having purchased on at the first "available" opportunity, or finding some other means to get to work. I assume for most normal people being an hour late on regular occasion equals the sack and so taking your chances on always having enough time to get off and buy a ticket is not an option.
The position is not common sense, and is in my view unjust. Never mind "shouldn't be a problem", how about making sure it "won't be a problem"?